/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package ai.platon.pulsar.crawl.filter;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Interface used to limit which URLs enter PulsarConstants. Used by the injector and the
 * db updater.
 */
public interface UrlFilter {

    Logger LOG = LoggerFactory.getLogger(UrlFilter.class);

    /*
     * Interface for a filter that transforms a URL: it can pass the original URL
     * through or "delete" the URL by returning null
     */
    String filter(String urlString);

    default boolean isValid(String urlString) {
        return filter(urlString) != null;
    }
}
